This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A194901 #5 Mar 30 2012 18:57:44 %S A194901 1,2,3,6,4,5,9,7,10,8,15,13,11,14,12,20,18,16,21,19,17,28,26,24,22,27, %T A194901 25,23,35,33,31,29,36,34,32,30,45,43,41,39,37,44,42,40,38,54,52,50,48, %U A194901 46,55,53,51,49,47,66,64,62,60,58,56,65,63,61,59,57,77,75,73 %N A194901 Inverse permutation of A194900; every positive integer occurs exactly once. %t A194901 (See A194900.) %Y A194901 Cf. A194899, A194900. %K A194901 nonn %O A194901 1,2 %A A194901 _Clark Kimberling_, Sep 05 2011